Fuel rails that are used to deliver fuel to individual fuel injectors of internal combustion engines are well known. A fuel rail assembly, also referred to herein simply as a fuel rail, is essentially an elongated tubular fuel manifold connected at an inlet end to a fuel supply system and having a plurality of ports for mating in any of various arrangements with a plurality of fuel injectors to be supplied. In what is referred to as a return-less system, a fuel return line does not fluidly connect the fuel rail back to the fuel supply system at a rail outlet end. In a “return” system, a fuel line fluidly connects the end of the fuel rail opposite the inlet end back to the fuel supply system. Typically, a fuel rail assembly includes a plurality of fuel injector sockets in communication with a manifold supply tube, the injectors being inserted into the sockets. Fuel rails are typically used on internal combustion engines with multi-point fuel injection systems.
Typically, a fuel injector is connected to a fuel rail using two different methods. In a first prior art method, a clip, such as a c-clip, is used to hold the injector to the fuel injector socket of the fuel rail. The clip also prevents the injector from rotating within the socket. In a second prior art method, a lower and an upper cushion hold the injector between the fuel injector socket and the intake manifold or the cylinder head. In this case the fuel injector socket typically includes a finger that prevents rotation of the injector within the socket. Both prior art methods utilize separate parts, such as the clip or the cushions, which creates extra costs and requires cycle time for installation. Therefore, it is desirable to reduce the number of parts required in the assembly of a fuel injection system.
Efforts to eliminate separate parts for the injector to fuel rail installation have been undertaken in more recent prior art with limited success. Features integrated within the fuel injector socket, the injector, or both, often required relatively tight tolerances, which may result in increased machining time and higher production costs.
U.S. Pat. No. 5,301,647, for example, teaches a fastening clip for integral formation with a portion of the body of a fuel injector and that provides attachment and retention. Modifications to the injector are needed to integrate a cylindrical wall including a plurality of apertures and catches.
U.S. Patent Application No. 2006/0065244, for example, discloses an integral device that provides rotational orientation while allowing axial sliding engagement of the fuel injector relative to the socket after assembly. Retention tabs integrated within the socket engage with corresponding grooves integrated within the injector.
What is needed in the art is a fuel injector to fuel rail connection that does not require separate parts or expensive machining operations.
What is further needed in the art is a relatively simple connection of a fuel injector to a fuel injector socket of a fuel rail that enables efficient assembly as well as disassembly if needed.
It is a principal object of the present invention to provide a method for connecting a fuel injector to a fuel rail that reduces manufacturing cycle time and provides easier package for shipping compared to current methods.